Housing for discharge tube



R. J. THOMAS ETAL 3,035,164

HOUSING FOR DISCHARGE TUBE May 15, 1962 Filed June 2l, 1957 INVENTORSRAYMOND J. THOMAS MICHAEL @,TES!

KM@ HM am ATTORN YS United States Patent 3,035,164 HOUSING FOR DISCHARGETUBE Raymond J. Thomas, New Brunswick, and Michael G. Tesi, Nutley, NJ.,assignors to Engelhard Hanovia, Inc., a corporation of New Jersey FiledJune 21, 1957, Ser. No. 667,146 2 Claims. (Cl. 240-11.4)

The present invention relates to a housing for discharge tubes and, morespecically, provides a housing wherein the tube is suspended inside ofthe housing.

In accordance With the invention, the housing has a substantiallyhelical spring enclosed inside of its end portion, one end of the springbearing against the housing and the other end bearing against thedischarge tube. Thereby heat conduction from the tube to the housing isgreatly reduced, the warm-up time decreases and the tube reaches itsoperating voltage more quickly. Further, the tube suspended between-springs inside of the housing is eiciently protected against mechanicalshocks and tubes of slight diierences of length can be mounted into thesame housing.

The invention will be further illustrated by reference to theaccompanying drawings, in which FIG. 1 is a longitudinal and fragmentarysection through one embodiment of the invention and FIG. 2 represents alongitudinal and fragmentary section through another embodiment of theinvention.

The housing for discharge tubes as shown in FIG. 1 consists of acylinder 4 of material transmissive to the radiation produced by thedischarge tube 6, e.g., glass. The end portion of the housing comprisesa metal sleeve 8 which envelops the cylinder 4, a disc 10 of heatresistant, eg., ceramic, material affixed to the sleeve 8 and a metalferrule 12 inserted tightly into the disc 10. An opening 14 in theferrule is provided for electrically connecting the discharge tube 6,all electrical parts not being shown.

inside of the described end portion of the housing, a substantiallyhelical spring 16 is provided, the main portion of the spring envelopingthe lead-in neck 18 of the tube 6 and being located within the ferrule12. At both ends, the spring 16 terminates into at spirals, the outerspiral 2i) being of decreasing diameter and enclosing the bottom portionof the lead-in neck 18, while the inner spiral 22 is of increasingdiameter and follows the shoulder formed by the ferrule 12 and the disc10.

The embodiment of the invention as shown in FIG. 2 is more particularlyintended for discharge tubes operating with higher currents, the tubebeing at a comparatively greater distance from the housing.

The end portion of the housing consists of a cup-shaped end enclosure24, made from heat resistant, e.g., ceramic, material and provided witha ange 26. The ange 26 is axed to a metal sleeve 27 and holds a collar28 of heat resistant material axially movable in a circular recess 39.into the space between the edge of the collar 28 and the wall of therecess 30, tabs 32 of spring material can be inserted and attached tothe collar 28. Upon the lead-in neck 18 and adjacent to the outersurface of the collar 28, a metal Washer 34 is mounted which holds thelast spiral of a spring 35 in a circular groove 36 in the face of thewasher. At the other end thereof, the

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spring bears against the bottom of the end enclosure 24.

The dimensions of the housing are chosen in such a Way that, accordingto the embodiment represented in FG. l, the yspring 16 is slightlyextended while the spring of FIG. 2 is subject to compression. In bothcases, tubes of slight differences in length can be mounted into thesame housing wherein they are suspended and protected against mechanicalshock. At the same time, heat conduction from the discharge tube -to thehousing is greatly reduced and the warm-up time of the tube shortened.

It will be obvious to those skilled in the art that many modificationsmay be made within the scope of the present invention without departingfrom the spirit thereof and the invention includes all suchmodifications.

What is claimed is:

l. In a mounting assembly for discharge tubes having an envelope whichterminates in at least one lead-in neck joined to the envelope along acircular area, an annular collar mounted around the lead-in neckadjacent said circular area, a housing surrounding said lead-in neck andsaid collar, a helical compression spring having a resilient centerportion and bearing with its outer end against said housing, the innerend of the spring bearing against said collar to lend resilient supportto the discharge tube, substantially the entire length of the lead-inneck being freely enveloped by the resilient portion of said helicalcompression spring to permit axial displacements of the neck within thespring helix, and a plurality of springs engaging the periphery of thecollar and bearing against the inner Wall of the housing to maintain thecollar substantially centered within the housing.

2. In a mounting arrangement for a discharge tube having a longitudinalaxis, means comprising a generally cylindrical lead-in neck secured toone end of said discharge tube for providing a first spring bearingsurface on the end of said tube which extends substantiallyperpendicularly to the axis of said tube, a housing surrounding saidlead-in neck, said housing terminating in a tubular end portion ofrestricted diameter to form a circular shoulder constituting a secondbearing surface, and a helical spring, the inner end of the springterminating in an enlarged dat spiral which bears against said shoulderas the second bearing surface, the outer end of the spring terminatingin a diminishing flat spiral which bears against the rst bearing surfaceat the outer end of the lead-in neck, said spring extending between saidbearing surfaces and freely enveloping said lead-in neck over theirlongitudinally coextensive lengths.

References Cited in the file of this patent UNITED STATES PATENTS1,044,757 Decker et al Nov. 19, 1912 1,938,001 Wilson Dec. 5, 19332,003,342 Cavanaugh June 4, 1935 2,118,437 Kayatt May 24, 1938 2,130,768Kresge Sept. 20, 1938 2,375,807 Miller May 15, 1945 2,654,870 MillerOct. 6, 1953 FOREIGN PATENTS 1,016,242 France Aug. 20, 1952 1,092,510France Nov. 10, 1954

